test(core): bring every sieval/core module over the 70% mutation bar

tests/unit/core/runners/test_resume_gate.py

@@ -8,6 +8,7 @@
 from sieval.core.runners.resume_gate import (
     ResumeAction,
     ResumeVersionError,
+    format_identity_reject_message,
     format_reject_message,
     resume_version_verdict,
 )
@@ -127,3 +128,254 @@ def test_meta_without_version_key_raises(self, tmp_path):
         (tmp_path / "meta.json").write_bytes(orjson.dumps({"deterministic": True}))
         with pytest.raises(ResumeVersionError):
             gate_resume_version(tmp_path, "0.6.0")
+
+
+class TestRejectReasonIdentifiesTheRule:
+    """Each rejection names *which* rule fired, not merely that one did.
+
+    The four reject reasons lead an operator to four different fixes — fix the
+    version string, reinstall a released build, pin a non-dev build, or match the
+    series. Asserting only that `reason` is non-empty lets any of them be swapped
+    for another without a test noticing, including a swap that sends the operator
+    somewhere useless.
+    """
+
+    def test_unparseable_says_so(self):
+        assert (
+            resume_version_verdict("not-a-version", "0.6.0").reason
+            == "version string is unparseable"
+        )
+
+    def test_unknown_version_says_so(self):
+        assert (
+            resume_version_verdict("0.0.0", "0.6.0").reason
+            == "version is unknown (0.0.0)"
+        )
+
+    def test_dev_build_says_so(self):
+        assert (
+            resume_version_verdict("0.6.0", "0.6.1.dev3+gxyz").reason
+            == "development/local build cannot be matched non-exactly"
+        )
+
+    def test_local_build_shares_the_dev_reason(self):
+        assert (
+            resume_version_verdict("0.6.0", "0.6.1+local").reason
+            == "development/local build cannot be matched non-exactly"
+        )
+
+    def test_series_break_says_so(self):
+        assert (
+            resume_version_verdict("0.6.0", "0.7.0").reason
+            == "incompatible version series"
+        )
+
+    def test_a_permitted_resume_carries_no_reason(self):
+        # `reason` is documented as populated only for REJECT; a stray reason on
+        # an accepted resume would surface as an operator-facing message about a
+        # run that was never blocked.
+        assert resume_version_verdict("0.6.0", "0.6.0").reason == ""
+        assert resume_version_verdict("0.6.0", "0.6.3").reason == ""
+
+
+class TestLadderPrecedence:
+    """The ladder's *order* is the contract, not just its membership."""
+
+    def test_exact_match_outranks_every_reject_rule(self):
+        # Resuming your own build is always allowed, even when the string would
+        # fail every later rule.
+        for v in ("0.0.0", "not-a-version", "0.5.1.dev24+gabc", "0.6.0+local"):
+            assert resume_version_verdict(v, v).action is ResumeAction.EXACT
+
+    def test_unparseable_outranks_the_unknown_check(self):
+        # An unparseable string cannot be compared to 0.0.0 at all, so it must be
+        # reported as unparseable rather than as "unknown".
+        assert (
+            resume_version_verdict("not-a-version", "0.0.0").reason
+            == "version string is unparseable"
+        )
+
+    def test_unknown_outranks_the_dev_check(self):
+        assert (
+            resume_version_verdict("0.0.0", "0.6.1.dev3+gxyz").reason
+            == "version is unknown (0.0.0)"
+        )
+
+    def test_dev_outranks_the_series_check(self):
+        # Different series *and* a dev build: the dev build is the actionable
+        # one, since matching the series would still not make it resumable.
+        assert (
+            resume_version_verdict("0.6.0", "1.2.0.dev1").reason
+            == "development/local build cannot be matched non-exactly"
+        )
+
+
+class TestBreakAxis:
+    """Under 1.0 the break axis is minor; from 1.0 on it is major."""
+
+    def test_patch_bumps_stay_compatible_under_1_0(self):
+        assert (
+            resume_version_verdict("0.6.0", "0.6.99").action is ResumeAction.COMPATIBLE
+        )
+
+    def test_minor_is_the_break_axis_under_1_0(self):
+        assert resume_version_verdict("0.6.9", "0.7.0").action is ResumeAction.REJECT
+
+    def test_minor_bumps_stay_compatible_from_1_0(self):
+        assert (
+            resume_version_verdict("1.0.0", "1.99.0").action is ResumeAction.COMPATIBLE
+        )
+
+    def test_major_is_the_break_axis_from_1_0(self):
+        assert resume_version_verdict("1.99.0", "2.0.0").action is ResumeAction.REJECT
+
+    def test_crossing_into_1_0_breaks(self):
+        # The axis itself changes here, so the pair is incompatible in both
+        # directions regardless of how close the numbers look.
+        assert resume_version_verdict("0.9.9", "1.0.0").action is ResumeAction.REJECT
+        assert resume_version_verdict("1.0.0", "0.9.9").action is ResumeAction.REJECT
+
+    def test_pinnable_prereleases_are_not_treated_as_dev_builds(self):
+        # A pre-release is a fixed artifact, unlike dev/local; it falls through
+        # to the series check rather than being rejected as unpinnable.
+        assert (
+            resume_version_verdict("0.6.0", "0.6.1rc1").action
+            is ResumeAction.COMPATIBLE
+        )
+        assert (
+            resume_version_verdict("0.6.0", "0.7.0rc1").reason
+            == "incompatible version series"
+        )
+
+
+class TestFormatIdentityRejectMessage:
+    """Previously untested entirely — 18 mutants with no test to see them.
+
+    This is the message shown when a result directory was produced by a
+    *different* task. Its own text states the stake: a finished run is matched by
+    path alone, so resuming here would hand back the persisted task's report as
+    this task's result without running a sample. The operator can only act on it
+    if it names both tasks and both ways out.
+    """
+
+    def _msg(self) -> str:
+        return format_identity_reject_message("gsm8k_0shot_gen", "math_500_0shot_gen")
+
+    def test_names_both_tasks(self):
+        msg = self._msg()
+        assert "gsm8k_0shot_gen" in msg
+        assert "math_500_0shot_gen" in msg
+
+    def test_distinguishes_persisted_from_current(self):
+        # Both names appear; without labels the operator cannot tell which is
+        # which, and the two fixes are not symmetric.
+        msg = self._msg()
+        persisted = msg.index("gsm8k_0shot_gen")
+        current = msg.index("math_500_0shot_gen")
+        assert msg.index("persisted") < persisted < current
+        assert "meta.json" in msg, "the operator has to know where to look"
+
+    def test_states_the_consequence(self):
+        msg = self._msg()
+        assert "without running a single sample" in msg
+
+    def test_offers_both_recovery_paths(self):
+        msg = self._msg()
+        assert "Remove the result_dir and start fresh" in msg
+        assert "Give this task its own result_dir" in msg
+
+    def test_leads_with_the_abort(self):
+        assert self._msg().startswith("Resume aborted:")
+
+
+class TestFormatRejectMessageStructure:
+    """The message body, not just that four substrings appear somewhere."""
+
+    def _msg(self) -> str:
+        return format_reject_message("0.6.0", "0.7.0", "incompatible version series")
+
+    def test_leads_with_the_abort_and_names_the_subject(self):
+        msg = self._msg()
+        assert msg.startswith("Resume aborted:")
+        assert "sieval version is incompatible" in msg
+
+    def test_labels_which_version_is_which(self):
+        msg = self._msg()
+        assert msg.index("persisted") < msg.index("0.6.0")
+        assert msg.index("current") < msg.index("0.7.0")
+        assert "meta.json" in msg
+
+    def test_carries_the_reason_under_its_label(self):
+        assert "reason: incompatible version series" in self._msg()
+
+    def test_offers_both_recovery_paths(self):
+        msg = self._msg()
+        assert "Remove the result_dir and start fresh" in msg
+        assert "Reinstall sieval matching the persisted version series" in msg
+
+    def test_the_two_builders_do_not_share_a_recovery_path(self):
+        # They abort for different reasons and the second option differs: a
+        # version mismatch is fixed by reinstalling, an identity mismatch by
+        # giving the task its own directory. Swapping them would send the
+        # operator down a route that cannot work.
+        version_msg = self._msg()
+        identity_msg = format_identity_reject_message("a_task", "b_task")
+        assert "Reinstall sieval" in version_msg
+        assert "Reinstall sieval" not in identity_msg
+        assert "its own result_dir" in identity_msg
+        assert "its own result_dir" not in version_msg
+
+
+class TestUnpinnableBuildsRejectOnEitherSide:
+    """`local` and `dev` are independent markers; either alone must reject.
+
+    The earlier run-side test used "0.6.1.dev3+gxyz", which carries *both*, so it
+    could not tell an `or` in this guard from an `and` — a build tagged only
+    local would have fallen through to the series check and resumed.
+    """
+
+    def test_local_only_on_the_run_side(self):
+        assert (
+            resume_version_verdict("0.6.1+local", "0.6.0").action is ResumeAction.REJECT
+        )
+
+    def test_dev_only_on_the_run_side(self):
+        assert (
+            resume_version_verdict("0.6.1.dev3", "0.6.0").action is ResumeAction.REJECT
+        )
+
+    def test_local_only_on_the_current_side(self):
+        assert (
+            resume_version_verdict("0.6.0", "0.6.1+local").action is ResumeAction.REJECT
+        )
+
+    def test_dev_only_on_the_current_side(self):
+        assert (
+            resume_version_verdict("0.6.0", "0.6.1.dev3").action is ResumeAction.REJECT
+        )
+
+
+class TestRejectMessagesExplainThemselves:
+    """The explanation is the load-bearing half of an operator message.
+
+    Both builders spell out *why* the abort happened. Without it the operator
+    sees two versions or two task names and a pair of options, with nothing to
+    choose between them.
+    """
+
+    def test_identity_message_explains_the_path_match(self):
+        msg = format_identity_reject_message("a_task", "b_task")
+        assert "a finished run is matched by path alone" in msg
+        assert "would hand back the persisted task's report" in msg
+
+    def test_version_message_names_the_incompatibility(self):
+        msg = format_reject_message("0.6.0", "0.7.0", "incompatible version series")
+        assert "sieval version is incompatible with the persisted run" in msg
+
+    def test_both_messages_end_on_an_actionable_choice(self):
+        for msg in (
+            format_identity_reject_message("a_task", "b_task"),
+            format_reject_message("0.6.0", "0.7.0", "series"),
+        ):
+            assert "Either:" in msg
+            assert "  1. " in msg and "  2. " in msg